scholarly journals Parameter optimization and mechanism research of enhanced coagulation treatment for Yuquan River water

2020 ◽  
Vol 20 (3) ◽  
pp. 1072-1082
Author(s):  
Qianshu Sun ◽  
Shuang Zhao ◽  
Yubo Yan ◽  
Wenlin Jia ◽  
Weihua Yang
Keyword(s):  
River Water ◽  
Removal Rate ◽  
Coagulation System ◽  
Optimal Dosage ◽  
Solution Ph ◽  
Enhanced Coagulation ◽  
Coagulation Mechanism ◽  
Xuzhou City ◽  
Initial Ph ◽  
Ph Range

Abstract As one of the drinking water sources for Xuzhou city, Yuquan River has been polluted seriously in recent years. In this paper, enhanced coagulation technology was selected and various parameters (coagulant species, dosage, solution pH and coagulant aid species) were optimized for Yuquan River water treatment. Turbidity and UV254 removal rate were calculated to assess coagulation efficiencies, and meanwhile floc generation kinetics, zeta potential and scanning electron microscope (SEM) spectra were measured to study the coagulation mechanism. Results indicated that the coagulation effect of polyaluminium chloride (PAC) on Yuquan River water was better than that of aluminium sulphate (AS), and its optimal dosage was 20 mg/L. Flocs produced by PAC also exhibited larger size and faster growth velocity than those of AS. Moreover, the applicable initial pH range for Yuquan River was 6.0–9.0, and the optimal coagulation efficiency was observed at pH 7.0. When PAC or AS was selected as coagulant, the application of sodium alginate (SA) could improve turbidity and UV254 removal due to its adsorption bridging role. In addition, coagulation efficiency could be enhanced in an AS coagulation system when polyacrylamide (PAM) was dosed as coagulant aid.

Preparation of a New Inorganic-Organic Composite Dual-Coagulant and Application of Oily Wastewater Treatment

2011 ◽  
Vol 233-235 ◽  
pp. 523-527 ◽  
Author(s):  
Song Jiang Ma ◽  
Mei Ling Fu ◽  
Fang Wen Li ◽  
Nian Fen Wu ◽  
Juan Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Removal Rate ◽  
Optimal Dosage ◽  
Oily Wastewater ◽  
Oil Removal ◽  
Treatment Efficiency ◽  
Coagulation Performance ◽  
Oily Wastewater Treatment ◽  
Ph Range ◽  
Scanning Electron

A new inorganic-organic composite dual-coagulant (PAFC-CPAM) was prepared by polyaluminum ferric chloride (PAFC) and cationic polyacrylamide (CPAM) and its treatment efficiency for oily wastewater was evaluated by coagulation jar tests. PAFC-CPAM dual-coagulants were characterized by FT-infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The FTIR spectra illustrated that there were some chemical reactions between PAFC and CPAM in PAFC-CPAM. SEM micrographs testified that PAFC-CPAM formed compact net structure which is different from PAFC and CPAM, resulting to its outstanding coagulation performance other than monomeric coagulant in treating oily wastewater. Coagulation jar tests presented that PAFC-CPAM improved 1.14% and 0.38% of oil removal rate and reduced 0.35NTU and 0.06NTU of residual turbidity than PAFC and CPAM respectively at the optimal dosage of 120mg/L. PAFC-CPAM enhanced 4.56% and 2.12% of oil removal efficiency and decreased 0.27NTU and 0.01NTU of residual turbidity on average in comparison with PAFC and CPAM respectively in the pH range of 4.0-8.0. All of above-mentioned experiment results demonstrated that PAFC-CPAM behaved superior coagulation performance than PAFC and CPAM.

scholarly journals Effect of Hydrogen Ion Presence in Adsorbent and Solution to Enhance Phosphate Adsorption

2021 ◽  
Vol 11 (6) ◽  
pp. 2777
Author(s):  
Taehoon Kim ◽  
Byungryul An
Keyword(s):  
Hydrochloric Acid ◽  
Adsorption Mechanism ◽  
Ph Effect ◽  
Total Surface Area ◽  
Point Of Zero Charge ◽  
Phosphate Adsorption ◽  
Hydrogen Ions ◽  
Solution Ph ◽  
Initial Ph ◽  
Ph Range

In this paper, the effect of hydrogen ions on the adsorption onto granular activated carbon (GAC) with the inorganic contaminant phosphate, which exists as a form of four species depending on the solution pH, is investigated. Various batch isotherm and kinetic experiments were conducted in an initial pH 4 as an acid, a pH 7 as neutral, and a pH 9 solution as a base for the GAC conditioned with deionized water and hydrochloric acid, referred to as GAC and GACA, respectively. The physical properties, such as the total surface area, pore volume, pore size distribution, and weight of the element, obtained from Brunauer–Emmett–Teller (BET) and scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM–EDX) represent no significant differences. However, the hydrochloric acid (HCl) condition results in an alteration of the pH of the point of zero charge from 4.5 to 6.0. The optimized initial pH was determined as being acid for the GAC and as being neutral for the GACA. According to the Langmuir isotherm, the relatively high Qm was obtained as being acid for the GAC and clearly distinguishes the pH effect as being the base for the GACA. An attempt was made to assess the adsorption mechanism using the pseudo-first-order (PFO), the pseudo-second-order (PSO), and the intraparticle diffusion models. The higher R2 for the PSO in the entire pH range indicated that chemisorption was predominant for phosphate adsorption, and the pH did not change the adsorption mechanism. A prolonged Bed Volume (BV) for the GACA demonstrated that the hydrogen ions on the surface of the GAC enhanced phosphate adsorption.

Factors influencing hydroquinone degradation in aqueous solution using a modified microelectrolysis method

2014 ◽  
Vol 71 (3) ◽  
pp. 397-404 ◽  
Author(s):  
Tong Li ◽  
Tingting Li ◽  
Houfeng Xiong ◽  
Donglei Zou
Keyword(s):  
Natural Waters ◽  
Removal Rate ◽  
Aquatic Organisms ◽  
Raw Material ◽  
Solution Ph ◽  
Factors Affecting ◽  
Metal Type ◽  
Mass Fractions ◽  
Initial Ph ◽  
Catalytic Metal

The discharge of hydroquinone (HQ), an important chemical raw material, to natural waters poses different ecological threats to aquatic organisms. In this study, we investigated the removal performance of traditional and modified microelectrolysis methods in aqueous solutions. The traditional microelectrolysis packing was modified by adding manganese (Mn), zinc (Zn), and copper (Cu) powder as additives. The factors affecting the removal performance of HQ, such as catalytic metal type, mass fraction of additive, reaction time, and initial pH, were examined. The results showed that the Mn modified packing exhibited the best performance compared to Zn and Cu powder. The removal rate of HQ using Mn modified packing can reach 94% after 4 h. In addition, 9% of Mn packing has a higher removal rate than other mass fractions. The acidic solution pH shows a more favorable degradation than a neutral and alkaline solution. The intermediates of HQ degradation by modified microelectrolysis were identified and then the pathway of HQ degradation was proposed. Our result indicates that Mn as catalytic metal holds promising potential to enhance HQ removal in water using the microelectrolysis method.

scholarly journals Enhancing the Removal of Sb (III) from Water: A Fe3O4@HCO Composite Adsorbent Caged in Sodium Alginate Microbeads

Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 44 ◽  
Author(s):  
Jun Zhang ◽  
Renjian Deng ◽  
Bozhi Ren ◽  
Mohammed Yaseen ◽  
Andrew Hursthouse
Keyword(s):  
Sodium Alginate ◽  
Large Scale ◽  
Diffusion Reaction ◽  
Order Kinetic ◽  
Solution Ph ◽  
Composite Adsorbent ◽  
Practical Applications ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Ph Range

To remove antimony (Sb) ions from water, a novel composite adsorbent was fabricated from ferriferous oxide and waste sludge from a chemical polishing process (Fe3O4@HCO) and encapsulated in sodium alginate (SAB). The SAB adsorbent performed well with 80%–96% removal of Sb (III) ions within a concentration range of 5–60 mg/L. The adsorption mechanism of Sb (III) was revealed to be the synergy of chemisorption (ion exchange) and physisorption (diffusion reaction). The adsorption isotherms and kinetics conformed to the Langmuir isotherm and the pesudo-second-order kinetic model. Both initial pH and temperature influenced the adsorption performance with no collapse of microbeads within solution pH range 3–7. Most importantly for practical applications, these microspheres can be separated and recovered from aqueous solution by a magnetic separation technology to facilitate large-scale treatment of antimony-containing wastewater.

Degradation of Orange IV Dye Solution Catalyzed by PVDF/Fe3+-TiO2 Catalytic Membrane in the Presence of H2O2

2010 ◽  
Vol 150-151 ◽  
pp. 1705-1709
Author(s):  
Ying Jie Zhang ◽  
Li Zhang ◽  
Xiao Fei Ma ◽  
Li Li ◽  
Jun Ma
Keyword(s):  
Reaction Rate ◽  
Removal Rate ◽  
Sol Gel ◽  
Reaction Rate Constant ◽  
Catalytic Membrane ◽  
Electron Hole ◽  
Membrane Area ◽  
First Order Kinetics ◽  
Initial Ph ◽  
Ph Range

A new heterogeneous PVDF/Fe3+-TiO2 catalytic membrane is prepared by sol-gel method, which had a well catalytic activity to decompose H2O2. The effect of initial pH, e initial concentration of H2O2 and Orange IV, temperature, and membrane area on the reaction rate is discussed. The PVDF/Fe3+-TiO2 catalytic membrane can effectively decolorize Orange IV in the pH range of 3.0-5.0. The optimal concentration of H2O2 is 15mmol/L. The reaction rate constant is proportional to the initial concentrations of Orange IV. The higher the temperature, the faster the reaction rate is, this reaction follows pseudo-first-order kinetics with activation energy of 1.54kJ/mol. Reuse of catalyst did not decrease the removal rate of Orange IV. The experiments of t-butanol, EDTA and XPS measurement showed that •OH, the electron hole and the ferryl are all the reactive species in the degradation of Orange IV.

scholarly journals Study of PFS and PAC coagulation effect on Pi River water

2021 ◽  
Vol 272 ◽  
pp. 01012
Author(s):  
Wan-Fen Wang
Keyword(s):  
Water Sample ◽  
River Water ◽  
Removal Efficiency ◽  
Aluminum Chloride ◽  
Ph Value ◽  
Removal Rate ◽  
Raw Water ◽  
Mass Ratio ◽  
Enhanced Coagulation ◽  
Better Than

Using poly-aluminum chloride (PAC) and poly-ferric sulfate (PFS) as coagulants, the effects of the dosage of PAC and PFS on the removal of turbidity, chromaticity and UV254* in water were investigated by using the method of enhanced coagulation. The results show that when the raw water is neutral and the turbidity is less than 20NTU, and the pH value does not decrease much after coagulation and sedimentation, PAC and PFS are separately added to 7.5mg/l, 35mg/l. The removal rate of turbidity and chromaticity in the water sample can reach 83.75% and 48.47%, respectively, but the removal rate of UV254* is less than 30%, the mass ratio of PAC to PFS is 1:1 to 6:1, the removal efficiency of turbidity and Chroma increased by about 10%, but the removal efficiency of UV254* did not change or even decreased, both PFS and PAC can effectively remove the turbidity and Chroma in the micro polluted Pi River, but the removal effect of UV254* is not good, and the removal effect of PAC is better than PFS.

Effects of CO2on Spray Solution pH

1995 ◽  
Vol 9 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Michael P. Braverman ◽  
James L. Griffin
Keyword(s):  
Deionized Water ◽  
Bicarbonate Concentration ◽  
Solution Ph ◽  
Spray System ◽  
Spray Solution ◽  
Initial Ph ◽  
Recovery From Acidification ◽  
Rate Of Recovery ◽  
Ph Decrease ◽  
Ph Range

The pH of deionized water, initially adjusted to a pH of 6 to 9, all decreased to near pH 5 upon pressurization with CO2in a backpack spray system. When deionized water contained bicarbonate (NaHCO3or KHCO3) at 0 to 800 mg/L to buffer against a pH decrease from CO2pressurization the return to their initial pH was more rapid than deionized water alone regardless of bicarbonate source. Acidification of spray solution following CO2pressurization of 138, 276, or 414 kPa was similar and bicarbonate had a greater effect than spray pressure. Addition of acidifying buffer and bicarbonate to the solution resulted in an initial and post-CO2pressurization pH range of less than one pH unit. All spray solution pH levels returned to near their initial pH following depressurization, indicating that the pH decrease was not permanent. Rate of recovery from acidification with CO2increased with initial pH and bicarbonate concentration.

scholarly journals Synthesis of MCM-41 stabilized NZVI and its use in removal of Cr(VI) from aqueous solution

2014 ◽  
Vol 5 (2) ◽  
pp. 149-156 ◽  
Author(s):  
Mang Lu ◽  
Yue Cheng ◽  
Jian-min Pan ◽  
Wen-jing Fan ◽  
Chuang Jiao ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Removal Rate ◽  
Kinetic Equations ◽  
Order Kinetic ◽  
Phase Reaction ◽  
Solution Ph ◽  
Transmission Electron ◽  
Initial Ph ◽  
Nano Zero Valent Iron ◽  
Mcm 41

In this study, MCM-41 stabilized nano zero-valent iron (M-NZVI) is synthesized using the rheological phase reaction method. Characterization with transmission electron microscopy validates the hypothesis that the introduction of MCM-41 leads to a decrease in aggregation of iron nanoparticles. X-ray diffraction confirms the existence of Fe0 and the strong antioxidant activity of Fe0 nanoparticles. Batch Cr(VI) reduction experiments exhibit that solution pH, M-NZVI dosage, and reaction time have significant effects on Cr(VI) removal. A high removal efficiency of Cr(VI) (84.5%) is obtained within 60 min for 100 mg/L of Cr(VI) solution at an initial pH of 6.0 and M-NZVI dosage of 0.5 g/L at 35 °C. The Cr(VI) removal rates follow modified pseudo-first-order kinetic equations. The observed removal rate constant was 0.0168/min for the M-NZVI dosage of 1.0 g/L. Our study suggests that the introduction of an innocuous stabilizer such as MCM-41 can significantly improve the performance of Fe0 nanoparticles for environmental remediation applications.

RemoVal of As (V) from Drinking Water by Attapulgite Loaded with Fe (III) Adsorbent

2013 ◽  
Vol 750-752 ◽  
pp. 1452-1456 ◽  
Author(s):  
Wan Ping Zhang ◽  
Hong Bo Xu ◽  
Jian Wang ◽  
Jing Wang ◽  
Bing Bing Wang
Keyword(s):  
Particle Size ◽  
Drinking Water ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Aqueous System ◽  
Arsenic Adsorption ◽  
Solution Ph ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Ph Range

An effective adsorbent for the removal of arsenate from aqueous system was synthesized by loading ferrihydrite on attapulgite (ATP). The effects of various parameters such as heat modified temperature and particle size of ATP, Fe (III) concentrations, adsorbent dosage, solution pH on the removal rate of arsenate were assessed. The results showed that 600 °C modified ATP loaded with Fe (III) sorbent had better arsenate removal efficiency than 200 °C and 400 °C modified ATP. The removal efficiency of As (V) increased significantly with decreasing the particle size of ATP. Arsenate was effectively adsorbed by ATP loaded with Fe (III) sorbent in the pH range of 57. Equilibrium data of arsenic adsorption fitted perfect with Langmuir isotherm model. The removal rate of As (V) by ATP loaded with Fe (III) sorbent was 95.8% at the optimal conditions from drinking water. The results showed that ATP loaded with Fe (III) sorbent can be used for the arsenate removal from aqueous system.

Color Removal of Reactive Brilliant Blue KN-R Simulated Dye Wastewater by Using Novel Flocculants

2012 ◽  
Vol 610-613 ◽  
pp. 1939-1942
Author(s):  
Ji Zhou Li ◽  
Xu Yin Yuan ◽  
Ming Tian ◽  
Hao Ran Ji ◽  
Wan Jiang
Keyword(s):  
Removal Efficiency ◽  
Color Removal ◽  
Brilliant Blue ◽  
Solution Temperature ◽  
Optimal Dosage ◽  
Dye Wastewater ◽  
Decolorization Efficiency ◽  
Initial Ph ◽  
Simulated Wastewater ◽  
Ph Range

In this study, five novel flocculants, QTRY-02, DC-491, Fennofix K97, BWD-01 and MD-03 were chosen to treat Reactive Brilliant Blue KN-R simulated wastewater by jar tests. The effect of flocculant dosage, initial pH, solution temperature of simulated dye wastewater and sedimentaion time on the color removal was examined respectively. The maximum color removal efficiency of KN-R was over 82% after 20 minutes of sedimentation and the optimal dosage was 150mg/L for all flocculants. In the pH range from 3 to 11, small changes in the color removal efficiency for QTRY-02. While for BWD-01, the efficiency increased from 67.3% to 88.3%. For both QTRY-02 and MD-04, decolorization efficiency increased as the solution temperature increased from 10°C to 50°C and the same result appeared when prolonging the sedimentation time from 1 to 12 hours.

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